Fuel blends

ABSTRACT

The invention provides a vehicle fuel composition containing an alcohol, a lubricant and an ether. A preferred embodiment is a fuel blend containing ethanol, dimethyl ether and a distilled organic acid. These fuel blends are thoroughly blended to obtain a motor fuel having a higher energy content and a lower pollution profile compared to standard commercial motor fuels.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. § 119(e)to U.S. Provisional Patent Application Ser. No. 60/910,721 filed Apr. 9,2007, which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to fuel compositions that may be used as fuels andas fuel additives for enhancing and stabilizing alcohol fuels andalcohol fuel blends.

BACKGROUND OF THE INVENTION

Due to the non-renewable nature of hydrocarbon fuels, considerableattention has been focused on development of alternate fuel sources.Oxygenated fuels containing ethanol or anhydrous ethanol have gainedwide technical acceptance. An oxygenated fuel is a fuel in which oxygenatoms are chemically bound within the fuel structure. The oxygen bond inthe oxygenated fuel is energetic and provides chemical energy thatresults in no loss of efficiency during combustion. Unfortunately,alcohol attracts water and will separate from petroleum fuels in thepresence of certain amounts of water condensation. Another problem isthat alcohol and particularly ethanol is generally denatured usingmethanol or with liquid natural gas (2-5%), which exacerbates theproblem of water separation and produces unacceptable solvency levels,such that ethanol/methanol/gasoline mixtures cannot be transportedthrough existing pipelines. Transportation is a major factor in the costand availability of alternative fuels (namely E10 and E85) to theconsumer, and there is no current use of pipeline transportation of E10or E85 for lack of technology that prevents ethanol/petroleum blendsfrom separating in the midst of water and causing corrosion.

Another problem associated with using ethanol as an oxygenate is thatethanol, as well as methanol and other water-soluble alcohols, will notmix at all with less refined fossil fuels, such as diesel fuel. Dieseloil and anhydrous ethanol form solutions when blended but the presenceof even a very low amount of water will cause a separation into ahydrocarbon phase and an ethanol/water phase. At lower temperatures, thetendency of phase separation increases. It is therefore important tomaintain the fuel in a homogeneous liquid phase over the entiretemperature range at which the fuel can be exposed.

Several methods of increasing the stability of a mixed fuel containingaqueous ethanol and hydrocarbons are known. For example, EP-A1-89 147discloses a macroemulsion comprising liquid hydrocarbons, ethanol andwater and as an emulsifier a polyetherpolystyrene block copolymer.However, the stability of such emulsions is limited and even minorseparations may cause disturbances when starting or running an internalcombustion engine, or causing increased emissions, for example of CO andorganic substances, when burnt.

Similarly, EP-A1-475 620 discloses a microemulsion diesel fuelcontaining a hydrocarbon fraction, water and optionally also ethanol. Inorder to form a microemulsion between the water phase and thehydrocarbon fraction, a blend of a hydrophilic surfactant and alipophilic surfactant is added, in particular a mixture of a sulfonateand an ethoxylate. This fuel needs large amounts of surfactants and isfurthermore rather sensitive to temperature variations.

Thus, there remains a need for ethanol fuel blends that do not separateinto different phases under typical operating conditions and can bepipelined in the presence of water that may condense in a pipeline orstorage tank without separation. These blends must retain the combustionproperties and renewable nature and favorable economics of alcohol fuelsand the beneficial effect on emissions, which initially spurred theinterest in hybrid fuels.

SUMMARY OF THE INVENTION

The present invention provides novel fuel compositions that may also beused as fuel additives for alcohol fuel blends. These fuel compositionsare produced from renewable sources and can be pipelined directly or inany combination with an alcohol without water separation. These fuelcompositions contain an ether and a lubricant component. These fuelblends may contain an alcohol, and particularly ethanol, in amountsrepresenting from between 1% to greater than 99% of the fuel blend.These fuel blends may also include petroleum fuel products such asgasoline or diesel fuels. Preferred fuel blends of this invention can beused independently of any petroleum products with the same compositionbenefits, but with better emissions profiles due do the elimination ofthe high carbon petroleum components.

The fuel blends of this invention may be mixed with petroleum gasoline.In any ratio, this gas-alcohol fuel additive blend will burn withfavorable emissions, better mileage and power and with no undesirableeffects in non-flex fuel engines. In embodiments containing ethanolconcentrations over about 60%, the vehicle merely requires amodification to the oxygen sensor. The ability of these fuel blends tobe used in all existing automobiles, without engine or fuel systemmodifications, is a novel advantage of these fuel blends.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 depicts a fractional distillation system that may be used toproduce an organic oil lubricant of the present invention.

DESCRIPTION OF THE INVENTION

The present invention is drawn to ethanol fuel blends that enhance thecombustion characteristics of the fuel while limiting the dryness andcorrosiveness of the fuel. The fuel blends of the present invention willnot separate under typical temperature and pressure conditions presentin an automotive engine. The fuel blends of the present invention areformed by combining an alcohol, an ether component, and a lubricant.

The alcohol is preferably ethanol, but methanol, as well as alcohols ofisomers of propane, butane, pentane, methoxypropane, hexane, heptane andoctane are also contemplated in the fuel blends of the presentinvention. Hydrocarbon fuels having a carbon number greater than three(i.e. propane) may have a higher flash point requiring the use of largeramounts, by volume, in the fuel mixtures of the present invention. Theselarger hydrocarbons may also impose greater environmental toxicities.

The alcohol may have any source. Preferably, the alcohol source islargely free of water. The anhydrous ethanol may be obtained from arenewable biomass source or other related sources. Preferably, theethanol is greater than 90% pure, more preferably more than 95% pure andeven more preferably, more than 99% pure. The anhydrous methanol oranhydrous ethanol as added in this invention may be 1% to 15% by volumeof the light hydrocarbon fraction, namely the pentane fraction. Thepercentage of the anhydrous methanol or anhydrous ethanol as added inthis invention may be optionally adjusted depending upon the desiredoctane number.

The ether component of the fuel blends of the present invention lowersthe vapor pressure for the fuel and thereby lowers the flash point ofthe fuel and acts as a primer to the combustion of the fuel. The ethercomponent is preferably diethyl ether, dimethyl ether or a combinationof these ethers. The ether component may be present in an amount between1% and 90%, by weight, of the fuel blend. The amount of ether added tothe fuel blends of the present invention may vary widely in response tothe altitude and temperature in which the fuels will be used, as well asthe amount and concentration of the lubricant present in the fuel.Preferably, the ether component of the fuel blends is diethyl etherpresent in an amount between 1% and 10%, by volume, of the fuel blend.

The lubricant component of the fuel blends of the present invention maybe any lubricant effective to offset the corrosiveness and dryness ofthe ether and ethanol portions of the fuel blend, while increasing theenergy content of the alcohol component of the fuel blend. The preferredlubricant is a mixture of hydrocarbons. Preferably, the hydrocarbons arerecovered from distilled organic oils. Oils derived from any plant,seed, bean, fruit or vegetable that has an oil component may bedistilled to produce the hydrocarbon blends that serve as lubricants inthe fuel blends of the present invention. Used cooking oils can also beused in the process. Petroleum and synthetic petroleum products may alsobe used to produce the hydrocarbon mixture but these hydrocarboncomponents will separate from the fuel blends over time, requiringcontinuous mixing. The lubricant component may be present in an amountbetween 0.001% and 99%, by volume, of the fuel blend. The lubricant maybe mixed with the alcohol in an amount between 0.008% and 0.02%, byvolume, of the fuel blend. The lubricants may also be used as a primarycomponent of a fuel, or used with the addition of only minor amounts ofether and ethanol as a bio-diesel fuel blend.

Thus, preferred fuel blends of the present invention contain ananhydrous alcohol containing between about 1% and about 10%, by volume,of an ether and between about 0.001% and about 0.1%, by volume, of amixture of distilled hydrocarbons. Preferably, the fuel blend is ananhydrous ethanol containing between about 1% and about 10%, by volume,diethyl ether and between about 0.001% and about 0.02%, by volume, of adistilled organic oil.

The lubricant components used in making the fuel blends of the presentinvention may be formed by distillation processes. The distillationprocesses used are described below, but one of skill in the art willreadily recognize that these processes may be scaled up to industrialdistiallation production volumes as desired.

Hydrocarbon lubricants may be produced by common fractional distillationof an organic oil. Referring to FIG. 1, any organic oil is introduced tothe round bottom flask (C) and an alcohol is introduced to the organicoil, preferably through a separatory flask (A) in connection with roundbottom flask (C). The round bottom flask (C) is heated using a heatsource (D) to a temperature in the range of between about 260° C. toabout 380° C., as may be measured by thermometer (B). Temperatures above380° C. may be used but the distillation produces excess quantities ofnatural gas at these temperatures while the production of the lubricantis reduced. Natural gas produced during the distillation is bled awayfrom the distilled lubricant from the condensing column (E) throughvacuum hose (J) to a natural gas containment vessel (L) under vacuumcreated by pump (K). Natural gas collected may be removed for usesoutside the distillation procedures of the present invention orre-introduced to the heat source (D). Hydrocarbon lubricant is collectedin collection flask (H) that is preferably cooled in an ice bath orother suitable cooling or refrigeration system (I). The condensingcolumn is cooled by circulating a coolant through coolant inlet (G) andreturned through coolant return line (F). Hydrocarbons collected incollection flask (H) may be further distilled to separate all fuel-gradehydrocarbons from any remaining glycerin.

The lubricant produced by common fractional distillation as describedabove can be further refined by common fractional distillation to removeadditional alcohols present. The lubricant is re-introduced to a roundbottom flask and heated to distill away any remaining alcohols.Preferably these additional alcohols are distilled through afractionating column and natural gas produced during the distillation isbled away from the distilled lubricant and alcohol vapor from thecondensing column through vacuum hose to a natural gas containmentvessel under vacuum. Natural gas collected may be removed for usesoutside the distillation procedures of the present invention orre-introduced as a heat source. A condensed and further refinedlubricant is retained in the round bottom flask. The condensed lubricantretained in the round bottom flask may be mixed with an alcohol to forma lubricant—alcohol fuel blend suitable for the intended temperature andaltitude at which the fuel will be used.

Diethyl ether may be produced by common fractional distillation ofsulfuric acid and ethanol. Referring again to FIG. 1, sulfuric acid isintroduced to the round bottom flask (C) and an alcohol is introduced tothe sulfuric acid, preferably through a separatory flask (A) inconnection with round bottom flask (C). The round bottom flask (C) isheated using a heat source (D) as measured by thermometer (B). Naturalgas produced during the distillation is bled away from the distilleddiethyl ether from the condensing column (E) through vacuum hose (J) toa containment vessel (L) under vacuum created by pump (K). Natural gascollected may be removed for uses outside the distillation procedures ofthe present invention or re-introduced to the heat source (D). Thecondensing column is cooled by circulating a coolant through coolantinlet (G) and returned through coolant return line (F). Diethyl ether iscollected in collection flask (H) that is preferably cooled in an icebath or other suitable cooling or refrigeration system (I).

The fuel blends of the invention may be used alone as a fuel or combinedwith gasoline or diesel or biodiesel fuels to improve the performance ordecrease the pollution created by burning typical gasolines, diesels,biodiesels or blends thereof. Reference to “fuel” or “gasoline” hereinis meant to encompass a fuel containing hydrocarbons boiling in thegasoline boiling point range of from 80° C. to 450° C., and preferablyfrom about 90° C. to about 400° C. When combined with the fuel blends ofthe present invention, the gasoline or diesel fuels obtain a higheroxygenate content meaning that the amount of oxygenate in the fuel maybe increased by at least about 5 volume percent, and preferably at leastabout 20 volume percent. The fuel blends of the present invention may beadded to gasoline or biodiesel fuels to obtain an alcohol content in thefinal hydrocarbonaceous fuel blend of about 20 volume percent or higher.Fuel blends of the present invention may be added to gasoline for use inall vehicles without adverse effects. For example, the fuel may beformed to include the fuel blends of the present invention such that theethanol content of the final fuel product is about 25 or about 50 orabout 75 volume percent in the fuel. While there is no known upper limiton the alcohol (or any oxygenate) content in a fuel that will benefitfrom the present invention, ethanol contents above about 80 volumepercent may have certain undesired corrosive effects. These fuelcompositions composed of fuel blends of the present invention combinedwith gasoline, diesel, and/or biodiesel, do not undergo phase separationunder typical fuel consumption operating conditions for periods ofgreater than 14 months. The lubricants used were found to be excellentstabilizers for the ethers and to impart a corrosion inhibiting propertyto the fuel blends.

The present invention also includes methods of improving the fueleconomy and reducing the pollutants produced by an internal combustionengine. These methods include using the fuel blends of the presentinvention to fuel an internal combustion engine. These oxygenated fuelsproduce fewer pollutants than the same engine fueled with a standardcommercial gasoline or diesel fuel. These enhanced fuels also have ahigher energy content compared to standard commercial fuels, owing tothe lubricant additives in the fuel blends of the present invention.

The present invention also provides a fuel production methodology andfacility that substantially reduces dependence on products imported tothe facility, other than the plant or animal feedstock used as a sourceof oil. The facility internally produces natural gases which arecollected in the production process for use in the facility. Theproduction process includes known processes of producing ethanolcombined with the distillation processes described herein. Ethanol,diethyl ether, water, lubricant/diesel, natural gas, and glycerin areall derived from grain or celluosic feedstock or any other feedstockthat can be utilized to produce all of these products. Ethanol isproduced from the feedstock and introduced to an organic oil (alsoderived from the feedstock) and by distillation produces the lubricantas described above. A portion of the lubricant is mixed with ethanol andether to produce a fuel blend of the present invention. Portions of thelubricant produced are also boiled down to produce a unique type of fuelsimilar to a diesel. Diethyl ether is produced as a byproduct of thevapor-phase hydration of ethylene to make ethanol. This process usessolid-supported phosphoric acid catalysts and can be adjusted to makespecific quantities of diethyl ether. Vapor-phase dehydration of ethanolover some alumina catalysts can give a yield of up to 95%. Diethyl etheris also produced by the acid ether synthesis mixing sulfuric acid andethanol. A nucleophollic oxygen atom of unprotonated ethanol displaces awater molecule from the protonated ethanol molecule, producing water, ahydrogen ion and diethyl ether. Water produced as by product may bereintroduced to facility operations. The glycerin that is collected isused as mass to collect, contain, and distribute the heat required inthe facility, via systems similar to typical hydronic heat systems. Theglycerin may be mixed with glycol or water to provide greater mass thantypical glycol or water hydronic systems. Natural gas is produced as abyproduct of the primary processes of ethanol, lubricant, diesel, anddiethyl ether, and collected for redistribution to energy production forthe facility. The remaining feedstock may be used to provide bio-massfor energy. This type of bio-mass derives from celluosic or otherfeedstocks, which would otherwise not be used to feed livestock. Othersources of energy may be required to supplement the natural gas butalternate sources of energy such as solar, geothermal, photovoltaictechnologies, and or other sources of methane may be applied to achievea self sufficient processing facility or a processing facility whichrelies primarily on alternative energies.

The foregoing description of the present invention has been presentedfor purposes of illustration and description. Furthermore, thedescription is not intended to limit the invention to the form disclosedherein. Consequently, variations and modifications commensurate with theabove teachings, and the skill or knowledge of the relevant art, arewithin the scope of the present invention. The embodiment describedhereinabove is further intended to explain the best mode known forpracticing the invention and to enable others skilled in the art toutilize the invention in such, or other, embodiments and with variousmodifications required by the particular applications or uses of thepresent invention. It is intended that the appended claims be construedto include alternative embodiments to the extent permitted by the priorart.

1. A fuel composition, comprising a homogeneous liquid phase comprisingan alcohol, an ether and an organic oil.
 2. The fuel composition ofclaim 1, wherein the alcohol is ethanol.
 3. The fuel composition ofclaim 2, wherein the ethanol is anhydrous ethanol.
 4. The fuelcomposition of claim 1, wherein the ether is selected from the groupconsisting of diethyl ether, dimethyl ether and combinations thereof. 5.The fuel composition of claim 1, wherein the organic oil is an oildistilled from a source selected from the group consisting of a plant, aseed, a bean a fruit and a vegetable.
 6. The fuel composition of claim1, wherein the organic oil is an oil distilled from used cooking oil. 7.A fuel composition, comprising a homogeneous liquid phase comprising: atleast about 80% by weight of an alcohol; about 1-10%, by volume, of atleast one ether selected from the group consisting of dimethyl ether anddiethyl ether; and, about 0.008-0.02%, by volume, of a distilled organicoil.
 8. A method of producing a hydrocarbon fuel additive comprising:mixing an organic oil with an alcohol to form an alcohol-oil mixture;heating the alcohol-oil mixture to a temperature of between about 260°C. to about 380° C. to produce a hydrocarbon gas; and, cooling thehydrocarbon gas to condense and capture a liquid hydrocarbon lubricant.9. The method of claim 8, further comprising capturing natural gasemitted from the heated alcohol-oil mixture.
 10. The method of claim 8,further comprising heating the liquid hydrocarbon lubricant to distilloff additional alcohol.
 11. A method of producing ether comprising:mixing sulfuric acid with an alcohol to form an alcohol-acid mixture;heating the alcohol-acid mixture to evaporate an ether gas; and, coolingthe ether gas to condense and capture a liquid ether.
 12. The method ofclaim 11, further comprising capturing natural gas emitted from theheated alcohol-oil mixture.
 13. A fuel composition, comprising ahomogeneous liquid phase comprising an alcohol, an ether and ahydrocarbon lubricant formed by the process comprising: mixing anorganic oil with an alcohol to form an alcohol-oil mixture; heating thealcohol-oil mixture to a temperature of between about 260° C. to about380° C. to produce a hydrocarbon gas; and, cooling the hydrocarbon gasto condense and capture a liquid hydrocarbon lubricant.
 14. The fuelcomposition of claim 13, wherein the alcohol is ethanol.
 15. The fuelcomposition of claim 13, wherein the ether is selected from the groupconsisting of diethyl ether, dimethyl ether and combinations thereof.16. A fuel blend comprising a homogeneous liquid phase comprising: apetroleum fuel selected from the group consisting of gasoline anddiesel; an alcohol; an ether; and, a hydrocarbon lubricant formed by theprocess comprising: mixing an organic oil with an alcohol to form analcohol-oil mixture; heating the alcohol-oil mixture to a temperature ofbetween about 260° C. to about 380° C. to produce a hydrocarbon gas;and, cooling the hydrocarbon gas to condense and capture a liquidhydrocarbon lubricant.
 17. The fuel blend of claim 16, wherein thealcohol content of the homogeneous liquid phase is between about 25volume percent and about 75 volume percent.